1. Field of the Invention
The present invention relates to a condenser.
2. Discussion of the Background
A condenser for a car air conditioner is known (see, for example, Japanese Patent Application Laid-Open (kokai) No. 2003-302126). The known condenser has a condensation section and a super-cooling section provided such that the former is located above the latter. A reservoir section is provided between the condensation section and the super-cooling section such that its longitudinal direction coincides with the vertical direction. The condenser section includes at least one heat exchange path formed by a plurality of heat exchange tubes disposed in parallel such that their longitudinal direction coincides with the left-right direction and they are spaced apart from one another in the vertical direction, and a condensation section outlet header section which communicates with a downstream end portion (with respect to the flow direction of refrigerant) of the lower-end heat exchange path of the condensation section. The super-cooling section includes at least one heat exchange path formed by a plurality of heat exchange tubes disposed in parallel such that their longitudinal direction coincides with the left-right direction and they are spaced apart from one another in the vertical direction, and a super-cooling section inlet header section which is disposed on the same side with respect to the left-right direction as the condensation section outlet header section and which communicates with an upstream end portion (with respect to the flow direction of refrigerant) of the upper-end heat exchange path of the super-cooling section. The lower end of the reservoir section is located below the lower end of the condensation section outlet header section, and the upper end of the reservoir section is located above the lower end of the condensation section outlet header section. The condenser includes a header tank which is provided on the left or right end side and to which all the heat exchange tubes of the condensation section and the super-cooling section are connected, and the reservoir section formed separately from the header tank. The header tank is divided to upper and lower sections by a partition wall. The condensation section outlet header section is provided in the upper section of the header tank, and the super-cooling section inlet header section is provided in the lower section of the header tank. The interior of the condensation section outlet header section communicates, through a first communication section, with a portion of the interior of the reservoir section located above the lower end of the condensation section outlet header section, and a portion of the interior of the reservoir section located below first communication section communicates, through a second communication section, with the interior of the super-cooling section inlet header section of the header tank. A refrigerant inflow opening through which liquid-phase dominant refrigerant flows into the reservoir section is provided at the reservoir-section-side end of the first communication section. The liquid-phase dominant refrigerant flowing out of the condensation section outlet header section passes through the first communication section and laterally flows into the reservoir section through the refrigerant inflow opening. The liquid-phase dominant refrigerant having flowed into the reservoir section flows into the super-cooling section inlet header section through the second communication section.
In the case where the condenser described in the publication is incorporated into a refrigeration cycle of a car air conditioner, in order to determine the amount of refrigerant charged into the car air conditioner, the relation between the degree of super-cooling and the amount of charged refrigerant is obtained, and a charge graph as shown in FIG. 11 is made. When a portion of the interior of the reservoir section located above the center of the refrigerant inflow opening of the first communication section is filled with liquid-phase refrigerant, a stable range (S) of the charge graph of FIG. 11 within which the degree of super-cooling is constant is obtained.